Selector switch control for automatic telephone systems



D. K. DU B OIS Oct. 31, 1950 3 Sheets$hee 2 Filed May 11, 1948 Nmm QWN MYN INVENTOR D. K. DUBO/S- ATTORNEY Oct. 31, 1950 D. K. DU BOIS 2,523,269

SELECTOR SWITCH CONTROL FOR AUTOMATIC TELEPHONE SYSTEMS Filed May 11, 1948 s Sheets-Sheet} I/WENTOR D; K. 01/50/5 ATTORNEY Patented Oct. 31 1950 SELECTOR SWITCH CONTROL FOR AUTO- MATIC TELEPHONE SYSTEMS Daniel King Du Bois, Watervliet, 'N. Y., assignor to American Telephone and Telegraph Companyya corporation of New York Application May 11, 1948, Serial No. 26 276 I 13 Claims. 1

This invention relates to telephone exchange systems employing mechanical switching devices and more particularly to impulse registering and translating devices for such systems.

The number of ofiices which may be connected by a given exchange system is indicated by the number of digits in the office codes. ,Obviously a two-digit code would permit selection among not more than one hundred offices but in practice this number would be decreased by the reservation of the digit zero for calls through an operatoris position and the absorption of a single impulse to avoid false operation due to accidents. A further decrease would be caused by the difficulty of finding office names having certain Thus the maxi initial combinations of letters. mum number of offices which may be reached is something less than eighty.

In exchange areas employing a two-digit code,

connections are usually established through the.

intermediation of a sender which registers the impulse series dialed by the calling subscriber and then automatically controls the routing of .the call and the connection of the calling subscribers line to the called subscribers line in accordance with the setting of the registers. An exchange system of this general type is disclosed in Patent 1,509,434 granted September 23, 1924 to Ottmar H. Kopp. In the system disclosed in this patent, asingle translator switch assembly is disclosed which is capable of being set into any one of forty code positions in response to the setting of the A and B code digit registers by the two ofiice code digits of a called line number dialed by a calling subscriber. For small exchange areas where the expected increase in subscriber lines will not require more offices than can be provided for by a single translator switch assembly having a maximum of forty office code positions, a sender of the type disclosed in' the Kopp patent is adequate.

It has, however, been realized that the inclosed in the patent to Kopp hereinbefore referred to, modified by the addition of a second translator switch assembly. When it is known at the time of installation that both translator switch assemblies will be necessary at the time of cut-over for service, both assemblies and the necessary circuits for selectively operating them,

as disclosed in the .patent to Caverly, would be provided. Howevenin smaller exchange areas where there appears to be no immediate prospects that a second translator switch assembly will be necessary, but where there is a possibility that sometime in the future a second translator switch assemblymay be needed, one translator switch assembly is initially installed and wired for operation and mounting space on the switch frame is reserved for the later installation of a second translator switch assembly.

In some exchange areas in which a single translator switch assembly has been installed in each sender, it has :been found that the growth of the exchange areashas been such as to indicate the necessity of installing more offices in each such area that may be served by senders of the single translator switch assembly type. Such senders could of course be equipped with additional translator assemblies if space has been re-.

served for them on the switch frames but such installation would entail considerable expense. In ofilces where no provision has been made for the mounting of additional translator assemblies the expense would be even greater because additional frames and cabling would be required. In systems employing senders of the type disclosed in the patents hereinbefore referred to,

the costly addition of second translator assemblies would be indicated even though a small number of additional code points would ever be required and far fewer than the forty additional code points which the added translator assembly would afiord.

.It is the object of the present invention to enable a single translator switch assembly to increase the number of code points beyond its terminal bankcapacity so that a single assembly may serve to control the establishment of connections to an increased number of offices.

This object is attained in accordance with the present invention by the provision of a grouping circuit comprising six relays to permit the grouping of two sets of codes in each half of the transis lator, each set requiring one translator point in each half and by a splitting circuit comprising a set of five relays to break down the hitherto rigid association of mated codes to permit each of them to be treated independently of the other.

Since complete telephone exchange systems of 'ateaeei the type to which the sender of the present invention is applicable have been disclosed in a number of patents in the prior art, only so much of an exchange system as is essential to an understanding of the invention has been disclosed herein. Reference is made to the patents hereinbef-ore referred to for a more complete disclosure of such circuits.

Referring to the drawings:

Figure 1 shows a calling subscribers substation, control relays of a sender associable with such line, a register control switch and the A and B code digit registers;

Fig. 2 shows the two translator switches comprising a single translator assembly and the two sets of grouping relays; and

Fig. 3 shows the relays of the splitting circuit. For a full disclosure of the invention, Fig. 2 should be placed to the right of Fig. 1 and Fig. 3 should be placed to the right of Fig. 2.

Each sender is provided with ayplurality of step-bystep registering devices. These devices may be or any desired character but are prefer ably of the type shown and described in Patent 1,472,465 granted October 20, 1923 to .O. F. Fors ber and R. M. DeVignier. Two of uch registers namely the A code digit register 140 and the B code digit register 160 are disclosed in Fig. l. A register control or steering switch I of the same type is utilized to direct the successive series of dialed impulses to the registering devices.

The translator assembly disclosed in Fig. 2 is of such simple construction that it has not been considered necessary to disclose its mechanism herein. Two arcuate contact banks, each comprising a plurality of contact sets and each contact set comprising a plurality of contacts, are arranged side by side and supported by a suitable frame. A brush shaft carrying two brush sets arranged to cooperate with the contact sets is mounted in operative relation to the contact banks in the same frame. The brush sets are 180 degr es apart in displacement, that is, they are diametrically opposite one another on the shaft and the arrangement/is such that when one brush set completes its travel over its associated contact bank the other brush set will begin its travel over its associated bank. The power is'transmitted to the shaft from a constantly rotating shaft by means of clutch discs controlled in the manner commonly employed for driving sequence switches. The power source is indicated in the present disclosure by the clutch magnets 20I and 22!. Since the brush sets are driven at high speed, stop magnets represented in the drawing by magnets 202 and 222 have been provided for each half of the translator assembly in orderto insure the stopping of the brush sets on the desired terminal set.

As the number of functions to be controlled by the translator assembly exceeds the number of arcs usually provided on a switch of this type, two switches 200 and 220 are provided and are rotated and stopped simultaneously so that they form essentiallyone translator switch.

The detailed operation Of the system is as follows:

When a calling subscriber for example at substation ltil, removes his receiver from the switchhook, the operation of hunting switche is initiated in the usual manner :whereby the calling line becomes connected with an idle sender; for

example, the sender, portions of which are disclosed in the drawing. When the idle sender is selected, a circuit is completed from ground through the balancing coil IIG, over one conductor of the subscribers line, through the substation thereof and then over the other conductor of the subscriber line and through the upper winding of the L relay IOI and through the central ofiice battery to ground. Relay Iill energizes and closes over its front contact an obvious circuit for the slow-to-release SR relay I32 which operates and ove its lower contacts establishes an obvious circuit for the SR1 relay I03 which also operates. Relay I03 upon operating, establishes a circuit from ground over its lower contacts, the normal bank contact and brush lZI of arc RC4 of the register control switch 529 and through the winding of the DT relay IM to the central ofiice battery. Relay I04 thereupon operates and establishes a circuit from ground over its contacts, through the lower winding of line relay IOI to the dial tone source. A tone current is induced from the dial tone source into the upper winding of relay lElI whereby the calling subscriber is notified by the dial tone which he hears in his receiver that he may dial the digits of the desired called line number. Relay Hi2 also prepares the impulse circuit for setting the A code digit register ME], which may be traced from the back contact of relay IIlI, over the upper contacts of relay 502, through the winding of the slow-to-release RA relay I05, over brush I22 and normal bank contact of arc RC6 of the register control switch I20, over the back contact of the PP relay I06, through the winding of stepping magnet I45 of the A code digit register I40 and through the upper winding of the ON relay I07 in parallel with resistor I08 to the central ofiice battery.

When the subscriber dials the first digit of the oflice code of the wanted line number, the circuit of relay i0l is opened a number of times corresponding to the numerical value of the code letter. At each interruption of its circuit, relay IOI deenergizes and its armature falls back opening the circuit of relay I02 which, however, being slow-to-release, remains energized during these short interruptions of its circuit. The deenergization of relay l0I connects ground over its back contact to the impulse circuit previously traced causing relays I05 and i0? and the stepping magnet M5 to operate in series. Magnet M5 releases at the end of each impulse when relay IiII reenergizes to advance the brushes oi register I40 one step. Relay I05 being slow-torelease remains energized until the completion of the series of impulses when it also deenergizes. The operation of relay I05 closes a circuit from the central ofiice battery through the lower winding of ON relay I07 in parallel with resistor I09, through the winding of stepping magnet I25 of the register control switch 12c and to ground over the contacts of relay I05. Magnet $25 is thus energized and remains energized until the deenergization of relay I05 at the end of the series of impulses when it releases to advance the brushes of switch I20 into engagement with the No. 1 contacts, of their associated arcs. It will be noted that each deenergization of relay IOI also closes a circuit from the central office battery through the winding of pulse help (PH) relay III], over the upper contacts of relay 5E3, the brush E23 and normal contact of arc RC5 of the register control switch [20, over the back contact of stepping magnet I45 of the A code digit register I40, over the back contact of relay I06, the normal contact of switch arc RC6 and brush I22, through the winding of relay I 05, the

6 upper contacts 'of relay I02 and to ground over the back contact of relay IOI. Relay I.I energizes and over its lower contacts connects ground to the Winding of relay I02 to insure that such relay remains energized during the interruptions of its circuit and over its uppe contacts connects ground to the previously traced circuit through the winding of v stepping magnet I45 until this magnet completely attracts its armature thus insuring the operation of magnet I 45 and the advanceof the brushes of register I40 one step.

With the brushes of register control switch I 20 now in engagement with the No. 1 contacts of their respective arcs, theimpulsing circuit extends from the back contact of relay IOI, over the upper contacts of relay I 02, through the winding of relay I05, brush I22-and the No. 1 contact of switch arc RC6, winding of stepping magnet I65 of the B code digit register I60 and through the upper winding of relay I01 and resistor I08 in parallel to the central ofiice battery. Each interruption of the line circuit due to the dialing of the second digit of the oflice code of the wanted line number, releases relay IOI to thereby close the impulse circuit through the winding magnet I65 and each opening of the impulsing circuit due to the reoperation of relay IOI causes the release of magnet I65 and the advance of the brushes of the code register I60 one step. As in the case of register I40, relay I05 remains energized throughout the series of impulses and holds stepping magnet I25 of the register control switch energized. At the completion of the series of impulses, magnet I25 releases and advances the brushes of the register control switch I20 one step into engagement with the No. 2 contacts of their respective arcs in which the impulse circuit is extended to thestepping magnet of the thousands digit register (not shown). The setting of the numerical registers takes place in a manner similar to that of the code registers and is shown and described in the above-identified Patent 1,509,434. The circuit above-traced for relay H0 is completed in the'second position of switch I20, over brushes I22 and I23 of switch I20 in engagement with the No. 1 contacts of their respective arcs and over the back contact of stepping magnet I65 to insure the proper advance of register I60 in response to each impulse.

In a sender employing a translator assembly of the type disclosed in Patent 1,509,434, hereinbefore referred to, the A6 and B6 arcs of the A and B code digit registers are reserved for use in connection with calls'routed to manual offices and on which calls the sender transmits codes of impulses to set a call indicator at the manual ofiice to display on lamps the number of the wanted line. Since in many instances all manual ofiices of an exchange area become ultimately converted by the installation of machine switching equipment for full mechanical operation, the A6 and B6 arcs of the code digit registers are no longer required for call indicator operation. In such cases, these switch arcs become available for other uses. These code register arcs have, in accordance with the present invention, been employed together with two sets of code group relays 230, 23I, 232 and 240, 2M, 242 for enabling an increase in ofiice code translations with the initially installed translator equipment.

The function of the code grouping relays is to permit the grouping of two sets of codes on each half of the translator assembly, each set requiring one translator point in each half. In the system to which the invention is applicable, each registration of the A and B code digits is translated into a plurality of selection controls which may include the control of the brush and group selection movements of thedistrict selector, generally known as district brush and district group selections, and the controliof the brush and group selection movements of the ofiice selector, generally known as office brush and oflice group selections.

For connection to some terminating offices, the district brush and group selections may be the same for more than one ofiice connection, the selective discrimination being made through different oilice brush and group selections. Also for connection to other connecting offices, the district brush and group selections may be different whereby difierent office selectors are selected on calls to several ofiices but the oflice brush and oilice group selections made at the selected oflice selectors may be the same for the several different ofiice connections.

The condition under which a set of codes may be grouped therefore, is that all selections be identical except (a) district brush and district group selections for routes not requiring ofiice selections (b) o'flice brush and ofiice group selectionsfor routes requiring ofilce selections. In accordance with the present invention, provision is made for two code groups in each half of the translator. As disclosed in Fig. 2, the set of code group relays 230, 23I and 232 has been allocated to two such groups, one in each half of the translator assembly, requiring the same ofiice brush and ofiice group selection controls for which one translation point is reserved in each half of the translator assembly and the other set of code group relays240, MI and 242 has been allocated to two other code groups one in each half of the translator assembly requiring the same district brush and district group selection controls for which one translator point is' reserved in each half of the translator assembly. For this purpose, the contacts of relays 230, 23I and 232 are cross-connected from the terminal I strips 260 and 26I to counting relays of the sender to control district brush and district group selections and the contacts of relays 240, 2 and 242'are cross-connected from the terminal strips 262 and 263 to the counting relays to control.

office brush and ofiice group selections.

It is to be understood however, that both sets of relays could be allocated either to provide four code groups, two ineach half of the translator assembly, for codes involving like district brush and group selection controls or to provide four code groups, two in each half of the translator assembly, for codes involving like :office brush and group selection controls. If the code group relays are allocated in the first manner, then the terminals of terminal strips 260. and 2 62 would be cross-connected to the counting relays for oflice brush selection control and the terminals of strips 26I and 263 would be crossconnected to the counting relays for oifice group selection control. If the code group relays are allocated in the second manner, then the terminals of terminal strips 260 and 262 would be cross-connected to the counting relays for district brush selection control and the terminals of strips 261 and 262 would be cross-connected to the counting relays for district group selection control. w V r The actual setting of the A and B code digit registers and the translator equipment for representative two-digit codes employing the code grouping feature of the invention will now be discussed.

It will be assumed that the wanted subscribers line terminates in an office listed as Genoa. The code dialed in this case is GI-Ev which will result in the sending of two series of impulses comprising four impulses and three impulses respectively. In this case the A code digit register I40 comes to rest with its brushes engaged with the No. 4 contacts of their respective arcs and the B code digit register IGD comes to rest with its brushes engaged with the N0. 3 contacts of their respective arcs. As soon as the register control switch I20 advances following the setting of the B code digit register I69, the circuit of start relay III is established from ground over the lower contacts of relay I03, brush I2I engaged with the No. 21 contact of its arc RC4, over the upper transfer contacts and through the winding of relay I II and to the central office battery. Relay I I I thereupon energizes and looks over its upper alternate contacts and connects ground over its lower contacts to brush I4I of the A code digit I40. A circuit is thereby completed over the No. 4 contact of arc A3 of the A code digit register, brush IBI of the B code digit register, the No. 3 contact of arc B3 upon which brush I5I is standing, over the cross-connection to crossconnection terminal CGA, it being assumed that the code 43 is one of a code group, thence through the winding of the CGA code group relay 230 to the central office battery.

Relay 23B is thereby energized and over its No. 3 right contacts establishes obvious circuits for the GB and C'GC code group relays 23I and 232. The operation of the set of code group relays 23B, 23I' and 232 is, in the case assumed, indicative of the fact that the code 43 dialed is one of a code group for Which the office brush and ofiice group selections will be the same. Relay 230' also connects ground over its right No. 3 contacts to cross-connection terminal CGC which it will be assumed is connected for the code group under consideration to the No. '7 contacts of the hunting arcs HBI and H132 of the right halves of the translator switches 200 and 220 to determine that the translator switches will be controlled to stop on the translation point I.

Similarly, other contacts of the arcs B2, B3, B4 and B5 of the B code digit register I60, could be cross-connected to cross-connection terminal CGA to cause the operation of the set of code 1 group relays 230, 23I and 232 and thereby the connection of ground to the No. '7 contacts of the hunting arcs of the right halves of the translator switches, should it be possible'to include other ofiice codes in the same code group as code 43 above discussed.

As an example of this, the dialing of the code letters I-L for a call to the Illinois office of the exchange area, resulting in-the setting of the A code digit register I into the position in which its brushes engage the No. 4 contacts of their respective arcs and in the setting of the B code digit register I60 into the position in which its brushes engage the No, 5' contacts of their respective arcs, would result in theconnec tion of ground to cross-connection terminal CGA and theoperation of relays 230, 23I' and 232'as previously described. Thus, the office code would be allocated to the same code group as code 43.

When the register control switch I23 advances, following the setting of the B code digit register I68, and relay III is operated, circuits are completed from-ground over the inner lower contacts of relay II'I, conductors H2 and H3 and over the back contacts of stop magnets 222 and 222 of the translator switches 20% and 229 and through the windings of clutch magnets 29I and 22I of such switches to the central office battery. These clutch magnets thereupon energize to clutch the brush shafts of the translator switches to the constantly operating drive shaft of the exchange whereby the brush' sets of the translator switches are advanced over their respective contact banks. When the hunting brush 2B3 engages the No. '7 contact of its arc, a circuit is established from ground applied to such contact as previously described to determine one of the code groups, over brush 203, the upper back contact of the TR. relay 251, through the winding of stop magnet 202' of switch 262 and resistor 299 to the central oflice battery and magnet 292 energizes to open the circuit of clutch magnet 2ElI to stop switch 260. Similarly, when brush 223 of switch 22t engages the No. '7 contact of its arc, a circuit is established from ground applied thereto by code group relay 238, over brush 223, the lower back contact of relay 25I, through the winding of stop magnet 222 of switch 222 and resistor 229 to the central ofiice battery and magnet 222 energizes to open the circuit of clutch magnet 22I to thereby stop switch 220.

With the brush 295 of the translator switch 259 arrested in engagement with the No. '7 contact of its are, a first circuit is established from ground over brush 205 and conductor 233 to cross-connection terminal TB, brush I42 of the A code digit register; thence, assuming that this brush is in engagement with the No. 4 contact of its are for the code-43 as previously described, over conductor I46 and the No. 1 left contacts of relay 230' to terminal 234 on the strip 265 which terminal is connected to the proper counting relay for controlling the district brush selection. Asecondcircuit is established from ground over brush 204 and the No. '7 contact of its arc and conductor 235' to cross-connection terminal TG, brush I62 of the B code digit register, thence, assuming that this brush is in engagement with the No. 3 contact of its arc for the code 43, over conductor I66 and the No. 3 right contacts of relay 23I to terminal 233' on the strip 2tI Which terminal is connected to the proper counting relay for controlling the district group selection If translator contact No. 7 has the district selections controlled by the settings of the A and B code digit registers as just described, then the oflice brush and group selections are controlled over translator contacts No. 7 in the usual manner (usually skip-ofiice). Over other arcs (not shown) of the switches 260 and 220 other selection controls are made in the usual manner.

On other office calls, allocated to the same code group served by the code point '3 in the right halves of the translator switches, the office brush and office group selections controlled from the arcs associated with translator brushes 225 and 225 will be made in the usual manner but the district brush and district group selection con-- trols under the control or the code group relays 238, 23I and 232 will differ in accordance with the position of the A ofiice code register brush I42 and the position of the B ofiice code register brush I62. Thus for a call having the office code 45 previously considered with brush M2'set on the No. 4 contact of its arc, the circuit previously traced over conductor I46 and the No. 1 left contacts of relay 230 to terminal 234 is completed to control district brush selection and a circuit is established from ground applied over translator brush 204 and the No. 7 contact of its associated arc to cross-connection terminal TG is extended over brush Hi2 and the No. contact of its arc, conductor I61 and the N0. 2 left contacts of relay 232 to terminal 238 on terminal strip Zfil for controlling district group selection.

As a further example, it will be assumed that the subscriber dials the number of a line which terminates in the Kenvil ofiice of the exchange area. The code dialed in this case is K-EI and will result in the sending of two series of impulses comprising five impulses and three impulses respectively. With brush M3 of the A code digit register M9, positioned. upon the No. 5 contacts of its arc A2, a circuit is established from ground over brush I23 and such contact, conductor Ml, through the winding of relay 25l to central office battery, and from conductor I41 to conductor 259, the winding of the FP relay 300 and thence to the central ofiice battery. Relays 25l and 3110 thereupon operate over this circuit, relay 38!) upon operating locking to off-normal ground over its lower alternate contacts and conductor 306. The operation of transfer relay 25! is indicative that a code point in the left halves of the translator switches is to be used.

In response to the dialing of the code KE having a numerical equivalent of 53. the A code digit register I la comes to rest with its brushes engaged with the No. 5 contacts of their respective arcs and the B code digit register llili comes to restwith its brushes engaged with the No. 3 contacts of their respective arcs. When ground is thereafter connected to brush I41 of register Ml] as previously described, a circuit is established over brush l4! and the No. 5 contact of switch arc A3, over brush lfil and the No. 3 contact of switch arc B3 cross-connection terminal C'GA, conductor lid and thence through the winding of code group relay 230 to the central oiiice battery. Relay 230 will therefore energize in turn causing the energization of relays 23! and 232 and the connection of ground to one of the hunt contacts in the left halves of the translator switches 265i and 220, assumed to be contact 1 No. 29, to determine that the translator switches Will be controlled to stop on translation point 29.

Similarly, other contacts of the arcs B2, B3, B6 and B5 of the B code digit register H30 could. be cross-connected to cross-connection terminal CGA to cause the operation of the set of code group relays 255i and 232 and thereb the connection of ground to the No. 29 contacts of the hunting arcs of the left halves of the translator switches should it be possible to include other office codes in the same code group as code 53 above discussed When the register control switch I20 advanced following the setting of the B code digit register and relay 5 l l operated, the previously traced circuits for the clutch. magnets 28! and HI of the switches 28% and 225.! are established and the brushes of such switches are advanced until the hunting brushes 2 3 and 226 engage the No. 29 contacts of their respective arcs, previously grounded through the operation of code group relay 233. 1

When brush 2% engaged the No. 29 contact of its are, a circuit is established over the upper;

impulses and five impulses respectively.

of stop magnet 292 of switch 200 and resistor 2B8 to the central office battery and when the brush 226 engages the No. 29 contact of its arc, a circuit is established over the lower front contact of relay 25], through the winding of stop magnet 222 of switch 220 and resistor 229 to the central oifice battery. Magnets 202 and 222 thereupon operate to open the circuits of clutch magnets Zfll and HI to thereby arrest the advance of the brushes-ofswitches 20D and 220. 7

With the brush 208 of translator switch2til arrested in engagement with the No. 29 contact of its are, a first circuit is established from ground over such brush andcontact, conductor 233, cross-connection terminal TB, thence over brush M2 of the A code digit register and the No. 5 contact of arc A6 of such register, conductor I48 and the No. 1 right contacts of relay 23!! to terminal 23! on terminal strip 280 which terminal is connected to the proper counting relay for controlling the district brush selection. A second circuit is established from ground over brush 201 and the No. 29 contact of its arc, conductor 235, cross-connection terminal TG, thence over brush I62 of the B code digit register and the No. 3 contact of arc B6, conductor IE6 and the No. 3 right contacts of relay 231 to terminal 235 on terminal strip 26! which terminal is connected to the proper counting relay for controlling the district group selection. If translator contact N0. 29 has the district selections controlled by the settings of the A and B code digit registers as==just described, then the ofnce brush and group selections are controlled over translator contacts No; 29 in the usual manner. Over other arcs (not shown). of the switches 229 and 222, other selection controls are made in the usual manner.

On other office calls allocated to the same code group served by code point 29 in the left halves of the translator switches, the office brush and ofiice group selection controls from the arcs associated with translator brushes 225 and 224 will be made as usual but the district brush and district group selection controls under the control of code group relays 23B, 23! and 232 will differ in accordance with the setting of brush I42 of the A code digit register and with the setting of brush I62 of the B code digit register. Code point 29 could be used on connections having codes requiring the same district selections and the office selections controlled by the settings of the A and B code digit registers.

It will now be assumed that two additional code groups are to be formed in which groups the district brush and group selections are the same but the office brush and group selections are different. For this purpose the winding of code group relay 24B is connected by conductor M5 to cross-connection terminal (3GB. It will now be assumed that a calling subscriber dials the number of a wanted line which terminates in the Olean ofiice of the exchange. The code dialed in .this case is O -L which will result in the sending of two series of impulses comprising six In this case the A code digit register Ml} comes to rest with its brushes engaged with the No. 6 contacts of their respective arcs and the B code digit register I60 comes to rest with its brushes in engagement with the No. 5 contacts of their respective arcs. When ground is thereafter connected to brush IM of register I40 as previously described, a circuit is established over brush Ml and the No. 6 contact of register arc A3, over brush hi3 and the No. 5 contact of register arc B4, crossconnection terminals GB, conductor I I and thence through the winding of the CGD code group relay 240 to the central office battery, whereupon relay 240 is energized and over its No. 3 right contacts establishes obvious circuits for the CGE and CGF code group relays 2M and 242. The operation of the set of code group relays 240, 24I and 242 is indicative of the fact that the code 65 dialed is one of a code group for which district brush and district group selections will be the same. Relay 246 also connects ground over its N o. 3 right contacts to cross-connection terminals CGD which it will be assumed is connected to the'No. contacts of the hunting arcs HBI and 1-132 of the right halves of the translator switches 2539 and 220 to determine that the translator switches will be controlled to stop on the translation point It].

Similarly, other contacts of the arcs B2, B3, B4 and B5 of the B code di it register I could be cross-connected to terminal CGB to cause the operation of the set of code group relays 240, MI and 242 and thereby the connection of ground to the No. 10 contacts of the hunting arcs of the right halves of the translator switches should it be possible to include other oflice codes in the same code group as code above discussed.

When the register control switch I29 has advanced after the setting of the B code digit register I60 to cause the operation of start relay I I l, the previously traced circuits for the clutch magnets 2IlI and 22I of switches 2G6 and 220 are established and, with transfer relay 25I unoperated since the A code digit is even, the brushes of each translator switch are advanced until the hunting brushes 203' and 223 engage the No. 10 contacts of their respective arcs grounded through the operation of code'group relay 240.

When brush 2&3 engages the No. 10 contact of its arc, a circuit is completed over the upper back contact of transfer relay 25 I, through the winding of stop magnet 202 of switch 200 and resistor 20.) to the central oflice battery and when brush 223 engages the No. 10 contact of its are a circuit is established over the lower back contact of relay 25L through the winding of stop magnet 222 of switch 220 and resistor 229 to the central office battery. Magnets 202 and 222' thereupon operate to open the circuits of the clutch magnets ZDI and 22! to thereby arrest the advance of the brushes of switches 200 and 220.

With the brush 225 of translator switch 200 in engagement with the No. 10 contact of its arc, a circuit is established from ground over brush 225, conductor 252, cross-connection terminal TB, thence over brush 5:32 of the A code digit register and the No. 6 contact of the arc A6, conductor I59 and over the No. 2 right contacts of code group relay 248 to terminal 245 of terminal strip 262 which terminal is connected to the proper counting relay to control the office brush selection. A second circuit is established from ground over brush 22A and the No. 10 contact of its arc, conductor 233, cross-section terminal TG, thence over brush I62 of the B code digit register and the No. 5 contact of its arc B6, conductor I61 and the No, 2 left contacts of code group relay 242 to terminal 246 of terminal strip 253 which terminal is connected with the proper counting relay to control the oiiice group selection. If translator contact No. 10 has the office selections controlled by the settings of the A and B code digit registers, as just described, then the district,

brush and group selections are controlled over translator contacts No. 16 in the usual manner. Over other arcs (not shown) of translator switches 20% and 220, other controls are exercised in the usual manner.

On other calls allocated to the same code group served by code point in in the right halves of the translator switches, the district brush and district group selection controls from the arcs associated with the brushes 205 and 28 3 will be made in the usual manner but the oiiice brush and oilice group selection controls under the control of the code group relays 23!], 2M and 24?. will difier in accordance with the position of the A office code digit register brush I42 and the position of the B office code digit register brush I62.

As a still further example, it will be assumed that the subscriber dials the number of a Wanted line which terminates in the Porter office of the exchange area. The code dialed in this case is PO which will result in the sending of two series of impulses comprising seven impulses and five impulses respectively. On this call the A code digit register ms comes to rest with its brushes engaged with the No. 7 contacts of their respective arcs and the B code digit register E52 comes to rest with its brushes engaged with the No. 5 contacts of their respective arcs. When ground is thereafter connected to brush I 'll oi register Hill, as previously described, a circuit is established over brush I il and the No. 7 contact of arc A3, over brush Efil and the No. 5 contact of arc B3, cross-connectio terminal CGB, conductor H5 and thence through the winding of code group relay 245 to the central office battery. Relay 245) will therefore energize in turn causing the energization of relays 2M and 2 32 and the connection of ground to the cross-connection terminal CGD. It will be assumed that for t code grouplthe No. 32 translator code point is assigned and that therefore terminal CGD is connected to the No. 32 contacts of the left halves of the hunting arcs of translator switches 29% and Similarly, other contacts of the arcs B2, B3, 13 3 and B5 of the B code digit register I60 could be cross-connected to cross-connection terminal 0GB to cause the operation of the set of code group relays ME), 245 and 2 ,2 and thereby the connection of ground to the No. 32 contacts of hunting arcs of the left halves of the translator switches, should it be possible to include other oifice codes in the same code group as code 15 above discussed,

As an example of this, the dialing or the S -U code for a call to the Sumner ofiice of the exchange area, resulting in the setting of the A code digit register M0 into the position in which its brushes engage the No. '7 contacts of their respective arcs and in the setting of the B code digit register $60 into the position in which its brushes engage the No. 8 contacts of their respective arcs will result in the connection of ground to crossconnection terminal CGB and the operation of relays 240, MI and 242 as previously described. Thus the code I8 would be allocated to the same code group as code 15.

With brush @415 of the A code digit register Mil, positioned upon the No. '7 contact of its arc A2, the circuit of transfer relay ZEI is established in the manner previously described. When the reg ister control switch I20 has advanced after the setting of the B code digit register see to cause the operation of start relay III, the previously traced circuits for the clutch magnets Bill and HI of switches 260 and 22K] are established and the brushes of such switches are advanced until the-"hunting brushes 206 and 226 engage the No. 32 contacts of their arcs previously grounded through the operation of code group relay 240.

When brushes 206 and 226 engage the No. 32 contacts of their arcs, the previously traced circuits for the stop magnets 202 and 222 of the translator switches 2110 and 220 are established over the front contacts of transfer'relay 25I and. such'magnets thereupon operate to arrest the advance of the brush sets of the switches.

With the brush 228 of translator switch 22!] arrested in engagement with the No. 32 terminal of its arc, a circuit 'is' established from ground over such brush and contact, conductor 252, cross-connection terminal TB, brush M2 and the No. 7 contact of arc A6 of the A code digit register, conductor 549 of the No. 3 left contacts of code group relay 24! to terminal 249 of terminal strip 252 which terminal is connected to the proper counting relay to control the ofiice brush selection. A second circuit is established from ground over brush 221 and the No. 32 contact of its arc, 'conductor 239, cross-connection terminal TG, brush I62 and the No. 5 contactof arc B6 of the B code digit register I60, conductor I61, the No. 2 left contacts of code group relay 242 to terminal ZtS on terminal strip 263 which terminal is connected to the proper counting relay to control the ofiice'gr-oup selection. If translator contact No. 32 has the office selections controlled by the settings of the A and B code digit registers, as just described, then the district brush and group selections are controlled over translator contacts No. 32 in the usual manner.

On other office calls allocated to the same code group served by code point 32 in the left'halves of the translator switches, the district brush and district group selection controls from the arcs associated with the brushes 208 and 2M will be as just described but the ofilce brush and oflice group selection controls under the control of the code group relays 249, 2M, and 242 will differ in accordance with the position of th brush I 42 of the A oflice code digit register and the position of the brush I62 of the B .ofiice code digit registerw' It will be noted that the code points of arc A3 of the A code digit register are paired and that the four pairs of code points are connected to the brushes associated with the B2, B3, B4 and B5 arcs of the B code digit register. Thus for example, the, office codes having the numerical digit equivalents 53-and 43', 55 and 45, '75 and 65, '78 and 68, and 93 and 83 constitute pairs. As may sometimes occur, one of the codes of the pair may be in-use and the other unused, but it has not always been possible to use the unused one of a pair. In accordance with a second feature of the present invention, it is possible to split any of the eighteen pairs of codes. This is accomplished by the provision of the TRI, TRZ, TR3, TR I and TR5 transfer relays, 3M to 305 inclusive. These relays are operable in response to the operation of the FP relay 359, when the brush I43 of the A code digit register is set upon an odd numbered operation of the ST relay II I as previously described, a circuit is established over brush MI and the No, 8 contact of its arc, over brush I64 and the No. 3 contact of its arc, conductor I68, terminal No. 5 of the terminal strip TO, the lower back contact of transfer relay 302, the No. 5 terminal of the terminal strip TA and conductor 301, which may for example be connected to the No. 4 contacts of the hunting arcs of the translator switches 20!] and 220.

When thereafter the translator switches are paused to hunt for the grounded contacts, their brushes will be brought to rest upon the No. 4 contacts of their respective arcs in the manner :reviously described and selection controls will be effective over such No. 4 contacts for establishing a connection to the office, the ofifice'code of which the calling subscriber has dialed.

Should the calling subscriber dial an office code of which. the A and B code letters have numerical values 9 and'3, that is, the other one of a pair of codes, then the brush MI of the A code digit register will be set upon the No. 9 contact of arc A3 and the brush I64 of the B code digit register will be set upon the No. 3'contact of arc B5. Also brush I43 of the A code digit register will be set on contactNo. 9 of arc A2 and. will establish the previously traced circuit for transfer relay 25I and relay 3G0. Relay 300 upon operating establishes over its upper contacts obvious operating circuits for transfer relays 3Ill and 392 and relay 30I upon operating establishes obvious circuits for transfer relays 303,305 and 395.

When ground is connected to brush MI following the operation of the ST relay I I I as previously described, a circuit is established over brush MI and the No. 9 contact of its arc, over brush I64 and the No. 3 contact of its arc, conductor I68, terminal No. 5 of the terminal strip TC, the lower front contact of operated transfer relay 3132, the No. 5 terminal of terminal strip TB which may for example be connected over conductor 303 to the No. 34 contacts of the hunting arcs of translator switches 29!] and 220.

When thereafter the translator switches are caused to hunt for the grounded contacts, their brushes will be brought to rest upon the No. 34 contacts of their respective arcs in the manner previously described and selection controls will then be effected over such No. 34 contacts for establishing a circuit'tothe office, the office code of which the calling subscriber has dialed. It will thus be noted that both pairs of the paired codes have been utilized.

It will now be assumed that of the pair of codes 56 and 46, one of the pair 46 is assigned to a code group CGA and that it is desirable to use the other of the pair 56. In this case, for example, the No. 1 terminal of terminal strip TC is connected to the No. 6 contact of arc B3 over conductor IE9, and the No. 1 terminal of terminal strip TA is connected over the lead IT! to code group cross-connection terminal CGA, and the No. 1 terminal of the terminal strip TB is connected over conductor 309 with available code points in the left halves of the hunting arcs HBI and HB2 of the translator switches 200 and 220, as for example code point 38'.

If the code 46 is dialed, in which case the A code digit register is set to register the digit 4 and the Bcode digit register is set to register the digit 6, then when ground is connected to brush Id! of the A code digit register, a circuit is established over brush I4! and the No.4 contact of its arc A3, over brush [El and the No. 6 contact of its arc B3, connected to the No. 1 terminal of terminal strip TC over conductor H69; thence over the upper back contact of transfer relay 36L the No. 1 terminal of terminal strip TA, conductor ill to cross-connection terminal CGA and thence through the winding of code group relay 236. Thereupon code group relays 230, 23| and 232 operate to control the selection of a translator code point and to control selections in the manner previously described.

With the A code digit register set to register the digit 5 and the code B digit register set to register the digit 5, ground connected to brush I43. will establish the circuit of relays 25l and 309 as previously described, resulting in the operation of transfer relays 39] to 305 inclusive. When ground is connected to brush Ml of the A code digit register, a circuit is established over brush M! and the No. 5 contact of its arc A3, brush [6! and the No. 6 contact of its arc B3 connected to terminal I of terminal strip TC over conductor I69, the upper front contact of transfer relay 31H, conductor 309 and to the No. 38 contacts of the hunting arcs with which brushes 206 and 225 are associated. The translator brushes will therefore be set upon the No. 38 terminals of their arcs for controlling the establishment of a connection to the ofiice, the office code of which is represented by the digits 56.

It will also be assumed that of the pair of codes 18 and 68, one of the pairs 18 is assigned to a code group CGB as previously described and that it is desirable to use the other of the pair 68. In this case, for example, the No. 18 terminal of terminal strip TC is connected to contact 8 of the B4 arc of the B code digit register over conductor Hi], and the No. 18 terminal of the terminal strip TA is connected over conductor 3? with available code points on the right halves of the hunting arc HB! and HB2 of the translator switches 20!! and 226, as for example to code point 2.

With the A code digit register set to register the digit 6 and the B code digit register set to A register the digit 8 and transfer relays 302, 303, 384 and'305 unoperated, when ground is connected to brush Mi of the A code digit register a circuit is established over brush I 4| and the No. 6 contact of its arc A3, over brush I63 and the No. 8 contact of its arc B4 connected over conductor Hi! to the No. 18 terminal of terminal strip TO, the inner lower back contact of relay 305, the No. 18 terminal of terminal strip TA, conductor 3! and to the No. 2 contacts of the hunting arcs with which brushes 203 and 223 of the translator switches are associated. The translator switches will therefore be set upon the No. 2 contacts of their arcs for controlling the establishment of the connection to the office, the oifice code of which is represented by the digits 68.

It is thus possible by the connection of the terminals of terminal strip TC directly to contacts of arcs B2, B3, B4 and B5 of the B code digit register I and b connecting similarly numbered terminals of the terminal strips TA and TB to contacts in the right and left halves of the hunting arcs of the translator switches to split any desired one or ones of the paired codes which are not assigned to any code groups or, b the connection of terminals on the TA, TB terminal strips to code group terminals CGA and CGB, to split any desired one or ones of paired codes, one code of each such pair having 16 been assigned to one or the other of the code groups. Thus by the grouping of codes and the splitting of paired codes, it is possible to considerably increase the number of offices which may be served without adding additional translator switches.

What is claimed is:

1. In a telephone system, means for controlling the establishment of connection over a plurality of routes each including a plurality of selection stages, comprising primary registering devices operable under the control of a calling subscriber, a secondary registering device operable into a plurality of route-determining positions, route grouping means, means operable under the joint control of aid primary registering devices for operating said route grouping means to group routes which require identical controls for certain selection stages thereof, means for operating said secondary registering device under the control of said route grouping means, and means controlled jointly by said grouping means and by said primary registering devices for selectively determining the controls for the other selection stages of said groups of routes.

2. In a telephone system, means for controlling the establishment of connections over a plurality of routes each including a plurality of selection stages, comprising primary registering devices operable under the control of a calling subscriber, a secondary registering device operable into a plurality of route-determinin positions, a plurality of route grouping means, means operable under the joint control of said primary registering devices for operating each of said route grouping means to group routes which require identical controls for certain selection stages thereof, means for operating said seC- ondary registering device under the control of said route grouping means, and means controlled jointly b said grouping means and by said primary registering devices for selectively determinin the controls for the other selection stages of said groups of routes.

3. In a telephone system, means for controlling the establishment of connections over a plurality of routes each including a plurality of selection stages, comprising primary registering devices operable under the control of a calling subscriber, a secondary registering device operable into a plurality of route-determining positions, means operable under the joint control of said primar registering devices for setting said secondary registering device to determine the controls for all selection stages of certain routes, a plurality of route grouping means each operable under the joint control of said primary registering devices for grouping routes which require identical controls for certain selection stages thereof, means controlled by said grouping means for controlling the setting of said secondary registering device, and means controlled jointly by said grouping means and by said primary registering devices for selectively determinin the controls for the other selection stages of said groups of routes.

4. In a telephone system, means for controlling the establishment of connections over a plurality of routes each including a plurality of selection stages, comprising primary registering devices operable under the control of a calling subscriber, a secondary registering device operable into a plurality of route-determining positions, a plurality of sets Of route grouping relays 17] each set operable under the joint control of said primary registering devices for grouping routes which require identical controls for certain selection stages thereof, means controlled by said sets of .relays for controlling the setting of said secondary registering device, into different routing positions, means controlled in the different routing positions of said secondary registering device for determining the controls for said certain selection stages of said groups of routes, and means controlled jointly by said sets of relays and bysaid primar registering devices for selectively determining the controls for the other selection stagesof said groups of routes. V

5. In a telephone system, means for controlling the establishment of connections over a plurality of routes each including a'plurality of selection stages, comprising primary registering devices operable under the control of a calling subscriber, a translator switch assembly having its switch arcs divided into two halves and operable into a plurality of route-determining positions,

route-determining position in one or the other of;

its halves dependent upon' the setting of, said one primary registering device, means controlled in g the different routing positions of said translator switch assembly for determining the controls for said certain'selection stages of said group of routes, and .means controlled jointly by said grouping means and by said primary registering devices for selectively determining the controls for the other selection 'stages'lof. said groups of routes.

6. In a telephone system, means forcontrolling the establishment, of connections over a plurality of routes each including a plurality of selection stages, comprising primary registering devices operable underthe control of a calling subscriber to register the oflice codes of wanted line numbers, said devices being arranged to group said codes in pairs, a translator switch assembly having its switch arcs divided into two halves and operable into a plurality of route-determining positions, means operable under the joint control of said primarynregistering devices for grouping routes which require identical controls for certain selection stages thereof, means controlled by said grouping means and by one of said primary registering devices for selectively controlling the setting of said translator switch assembly into a route-determining position in one or the other of itshalves dependent upon which one of a pair of codes has been registered, means controlled in the difierent routing positions of said translator switch assembly for determining the controls for said certain selection stages of said groups of routes, and means controlled jointly by said grouping means and by said primary registering devices for selectively determining the controls for the other selection stages of said groups of routes.

7. In a telephone system, means for controlling the establishment of connections over a plurality of routes, comprising primary registering devices operable under the control of a calling subscriber, a secondary registering device operable into a plurality of route-determining positions, relay means operable in response to the registering devices when the first digit of a;

setting of the first of said primary registering devices when the first digit dialed is odd, and means jointly controlled by said relay means {and said primary registering devices for controlling the setting of said secondary registering device into positions determined jointly by the ',nu-. merical values of the settings of the primary registeringdevices and by the odd oreven nu merical value of the setting of the first of said primary registering devices. g l

8. In a telephone system, means for controlling the establishment of connections over a plurality of routes, comprising primary registering devices operable under thecontrol of a calling subscriber to register the ofiice codes of wanted line numbers, said devices being arranged-to group said codes in pairs, a secondary registering device operable into a plurality of routele termining positions, relay means operable .inIr-J sponse to the setting of-the first of said pri ary 'tered code pair is odd, and means jointl co'n trolled by said relay means and bysaid primary registering devicesfor-controlling thesetting of said secondary registering deviceinto difierent routing positions for each code of any pantiregistered codes. i

V 9. In a telephone system, means forcontrollin'g' the establishment of connections overa plurality of routes, comprising primary registering devices operable under the control of a calling subscriber to register the officecodes of wantedline,numbers, said devices being arranged to group said codes in pairs, a translator switch assembly hav ing its switch arcs divided into twoflialves'and operable into a pluralityp-f routeedeterrnining po:

sitions, relay, means operable in 'respo nse toflth ei setting of the-,ifirst of said primary registering devices when, the first'digit of a registered fcpde' pair is odd, and means jointly controlledby said relay means and by said primary-registerin'gd vices for controlling the'setting of said translator switchass'embly into a route-determining .po'si tion in one. or'the other of its halvesdepend'en t upon which one of anypair of'codes has, been registered ,by said primary registering devices. 10 In a telephonesystem, means' for,-; con-. trolling-the establishment of connections oven a plurality of routes each including a plurality f selection stages, comprising primary registering devices operable under the control of a calling subscriber to register the office codes of wanted line numbers, said devices being arranged to group said codes in pairs, a translator switch assembly having its switch arcs divided into two halves and operable into a plurality of route-determining positions, means operable under the joint control of said primary registering devices for grouping routes which require identical controls for certain selection stages thereof, relay means operable in response to the setting of said primary registering devices when the first digit of a registered code pair is odd, means jointly controlled by said grouping means and by said relay means for controlling the setting of said translator switch assembly into a routedetermining position in one or the other of its halves dependent upon which one of a pair of codes is registered and assigned to a groupof routes, means controlled in said grouped route position of said translator switch assembly for determining the control for said certain selection stages, means controlled in said grouped route position jointly by said routing means and by said primary registering devices for selectively determining the controls for the other selection stages of said group of routes, and means jointly controlled by said relay means and by said primary registering devices if the other of a pair of codes has been registered but not assigned to the group of routes for controlling the setting of said translator switch assembly into a route-determining position in the half to which the group of routes has not been assigned.

11. In a telephone system, means for controlling theestablishment of connections over a plurality of routes each including a plurality of selection stages, comprising primary registering devices operable under the control of a calling subscriber to register the office codes of wanted line numbers,said devices being arranged to group said codes in pairs, a translator switch assembly having its switch arcs divided into two halves and operable into a plurality, of route-determining positions, means operable under the joint control ofsaid primary registering devices for grouping routes which require identical controls for certain selection stages thereof, relay means operable in response to the setting of said primary registering deviceswhen the first digit of a registered code pair is odd, means jointly controlled by said grouping means and by said relay means for. controlling the setting of said translator switch assembly into a route-determining position in one or the other of its halves dependent upon which one of the pair of codes has been registered, means controlled in certain of the routing positions of said translator switch assembly for determining the controls for said certain selection stages, means controlled in said certain routing positions jointly by said primary registeringdevices and by said routing means for selectively determining the controls for the otherselection stages of said groups'or" routes, and means jointly controlled by said relay means and by said primary registering devices for controlling the setting of said translator switch assembly into a route-determining position in one or the other of its halves dependent upon the second codes of pairs, the first codes of which pairs have been grouped.

12. Ina telephone system, a translating device for obtaining switching directions from the dialed digits or ofiice codes, comprising a primary registering device operable for registering plural digitofiice codes, terminals which may be marked with potentials into a plurality of conditions representative of switching directions, code grouping means operable under the control of said primary registering device for grouping codes, each group including codes differing from each other by one of said digits, and means controlled jointly by said grouping means and by the registration of said one digit by said primary registering device for connecting potential to said terminals to condition them to derive a switching directive translation from the particular office code registered in said primary registering device.

13; In a telephone system, a translating device for obtaining switching directions from the dialed digits of a subscribers line designation, comprising a primary registering device operable for registering sets 'of untranslated digit information, a secondary registering device for registering translated information, grouping means responsive to the setting of said primary registering device for grouping sets of untranslated information, each group including'a plurality. of sets of untranslated information and the sets of each group differing from-each other by an item thereof, means controlled by said grouping means for conditioning a'portion of said secondary registering device in the same manner for all sets of a given group of untranslated information, and means controlled jointly by said grouping means and by saidprimary registering device for conditioning another portion of said secondary reg- I istering device in a manner peculiar to the par ticular set of untranslated information registered in said primary registering device.

DANIEL KING DU BOIS.

REFERENCES CITED The following references are of record in the file of this patent:

. -UNITED STATES PATENTS 

